The Old Testament is filled with biblical prophecy, historical facts, and archaeological and scientific discoveries, along with Israel’s history and its importance to God. It displays God’s holiness, power, judgment, His character and His ways. The foundation for government, waging war, and moral law is also given in the Old Testament.
Many people believe we no longer need to read or observe the Old Testament since Christians live under the New Testament, however there is nothing to support this belief. In fact, Jesus quoted the Old Testament 28 times, and it is quoted 53 times by Matthew Mark, Luke, John, John the Baptist, Paul and Peter. The new didn’t start until after Jesus' death and resurrection so do we ignore all that Jesus said prior to that?